Bridge repair project just about completed
- Bill Sheehy
- Central Oregonian - News
ODOT crews are installing plates at measured distances on the roadbed of the bridge over the Crooked River, which are connected to other plates under the beams that support the bridge. These are drawn together by long threaded bolts. The series of bolted plates run the length of the bridge in two rows. As one row is completed, a layer of asphalt will be poured over the bolt-heads. After the other row is completely covered, a final layer of asphalt will be installed and the job will be completed. By this time next week, the work is expected to be finished and restricted traffic across the bridge only a memory.
>Thanks to a local business, the repair project that will make the bridge over the Crooked River last a few years longer is expected to be finished earlier than first expected
The end is near for completion of the repair work on the bridge over the Crooked River at the west end of town. Unless there is a problem with the weather, ODOT bridge crews expect to wrap up the job by the middle of next week.
Work on the project has gone quite smoothly, according to Dan Knoll, ODOT's Information Representative for the region. ODOT officials were very aware of the importance of the bridge to the local economy and gave the repairs a high priority.
"This bridge was built in the 1940s and had a life expectancy at that time of about 50 years. It's about at the end of that now," Knoll said.
Repairing the series of the shear cracks discovered during an inspection is expected to add another four to six years of life to the span.
Once the cracks in the beams holding up the upper layer were discovered, ODOT engineers determined the best way to fix the problem. At the same time the weight limit was reduced and will be closely monitored. When the bridge was constructed, nobody thought about the heavy loads that are common today. For years little was done and loads weighing more than 100,000 pounds were the norm. Now the upper weight limit is set at 85,000 pounds.
Workers have used an epoxy compound on the cracks and now are placing clamps or stirrups to hold the repaired cracks closed. Large, flat metal plates are placed under the beams and connected to identical plates above on the roadbed. These are drawn together by long threaded bolts. The series of bolted plates run the length of the bridge in two rows.
As one row is completed, a layer of asphalt will be poured over the bolt-heads. After the other row is completely covered, a final layer of asphalt will be installed and the job will be completed. That final paving is expected to be completed by Wednesday of next week.
Having the bridge made safer is not the only benefit the ODOT bridge crew brought to Prineville. Project Foreman Jim Stone explained that special tapered washers, engineered and ordered from a company in Portland, were unusable.
"We would have had to shut down for a week or more, if we would have gone back to Portland," Stone said. "We took the job to Duckett Welding here in Prineville and they dropped everything and went to work. I can't say enough good things about those guys," Stone added. "They kept us on schedule."
Knoll said even then, he believes the project is ahead of schedule.
The bridge crews expect to pave one side of the bridge today and work be ready to pave the other side Monday. The final overlay is set to be put down a couple days later.